package com.issc.framework.util;

import java.util.Scanner;

public class Client {
    public final static int a=2000;

    public static void main(String[] args) {
        int c=1000;
        int b=Integer.MAX_VALUE;
        Scanner input = new Scanner(System.in);
        while (input.hasNext()) {
            int o = input.nextInt();
            if (o > 0 && o + c < a) {
                System.out.println(o);
            } else {
                System.out.println("error");
            }
        }
    }
}
